English
Related papers

Related papers: Obstacles to State Preparation and Variational Opt…

200 papers

We present a general framework for modifying quantum approximate optimization algorithms (QAOA) to solve constrained network flow problems. By exploiting an analogy between flow constraints and Gauss's law for electromagnetism, we design…

Quantum Physics · Physics 2021-07-28 Yuxuan Zhang , Ruizhe Zhang , Andrew C. Potter

Quantum PCP conjecture is one of the most influential open problems in quantum complexity theory, which states that approximating the ground state energy for a sparse local Hamiltonian upto a constant is QMA-complete. However, even though…

Quantum Physics · Physics 2025-02-24 Kartik Anand

Adiabatic state preparation provides an analytical solution for generating the ground state of a target Hamiltonian, starting from an easily prepared ground state of the initial Hamiltonian. While effective for time-dependent Hamiltonians…

Quantum Physics · Physics 2026-01-21 Zekun He , A. F. Kemper , J. K. Freericks

We show that the two-dimensional (2D) local Hamiltonian problem with the constraint that the ground state obeys area laws is QMA-complete. We also prove similar results in 2D translation-invariant systems and for the 3D Heisenberg and…

Strongly Correlated Electrons · Physics 2021-08-03 Yichen Huang

Combinatorial optimization is a promising area for achieving quantum speedup. Quantum approximate optimization algorithm (QAOA) is designed to search for low-energy states of the Ising model, which correspond to near-optimal solutions of…

Quantum Physics · Physics 2025-10-14 Tatsuhiko Shirai , Nozomu Togawa

The quantum approximate optimization algorithm (QAOA) conceived for solving combinatorial optimization problems has attracted significant interest since it can be run on the existing noisy intermediate-scale quantum (NISQ) devices. A…

Information Theory · Computer Science 2022-04-12 Jingjing Cui , Gui Lu Long , Lajos Hanzo

Characterizing the entanglement structure of ground states of local Hamiltonians is a fundamental problem in quantum information. In this work we study the computational complexity of this problem, given the Hamiltonian as input. Our main…

Quantum Physics · Physics 2024-11-08 Adam Bouland , Chenyi Zhang , Zixin Zhou

A central result in the study of Quantum Hamiltonian Complexity is that the k-Local hamiltonian problem is QMA-complete. In that problem, we must decide if the lowest eigenvalue of a Hamiltonian is bounded below some value, or above…

Quantum Physics · Physics 2017-09-20 Naïri Usher , Matty J. Hoban , Dan E. Browne

We present a comparison of different quantum state preparation algorithms and their overall efficiency for the Schwinger model with a theta term. While adiabatic state preparation (ASP) is proved to be effective, in practice it leads to…

High Energy Physics - Lattice · Physics 2024-11-04 Alexei Bazavov , Brandon Henke , Leon Hostetler , Dean Lee , Huey-Wen Lin , Giovanni Pederiva , Andrea Shindler

Variational quantum algorithms, such as the Recursive Quantum Approximate Optimization Algorithm (RQAOA), have become increasingly popular, offering promising avenues for employing Noisy Intermediate-Scale Quantum devices to address…

Emerging Technologies · Computer Science 2025-06-04 Shuaiqun Pan , Yash J. Patel , Aneta Neumann , Frank Neumann , Thomas Bäck , Hao Wang

The Quantum Approximate Optimisation Algorithm (QAOA) is a widely studied quantum-classical iterative heuristic for combinatorial optimisation. While QAOA targets problems in complexity class NP, the classical optimisation procedure…

Quantum Physics · Physics 2025-11-12 Tom Krüger , Wolfgang Mauerer

We study the stability with respect to a broad class of perturbations of gapped ground state phases of quantum spin systems defined by frustration-free Hamiltonians. The core result of this work is a proof using the…

Mathematical Physics · Physics 2023-01-04 Bruno Nachtergaele , Robert Sims , Amanda Young

Estimating ground state energies of many-body Hamiltonians is a central task in many areas of quantum physics. In this work, we give quantum algorithms which, given any $k$-body Hamiltonian $H$, compute an estimate for the ground state…

Quantum computing holds promise for outperforming classical computing in specialized applications such as optimization. With current Noisy Intermediate Scale Quantum (NISQ) devices, only variational quantum algorithms like the Quantum…

Quantum Physics · Physics 2024-07-08 Daniel Müssig , Markus Wappler , Steve Lenk , Jörg Lässig

The local Hamiltonian (LH) problem is the canonical $\mathsf{QMA}$-complete problem introduced by Kitaev. In this paper, we show its hardness in a very strong sense: we show that the 3-local Hamiltonian problem on $n$ qubits cannot be…

Quantum Physics · Physics 2026-02-17 Nai-Hui Chia , Atsuya Hasegawa , François Le Gall , Yu-Ching Shen

We exploit insights into the geometry of bosonic and fermionic Gaussian states to develop an efficient local optimization algorithm to extremize arbitrary functions on these families of states. The method is based on notions of gradient…

Quantum Physics · Physics 2021-03-17 Bennet Windt , Alexander Jahn , Jens Eisert , Lucas Hackl

This paper presents the Maximum Amplification Optimisation Algorithm (MAOA), a novel quantum algorithm designed for combinatorial optimisation in the restricted circuit depth context of near-term quantum computing. The MAOA first produces a…

Quantum Physics · Physics 2022-06-02 Tavis Bennett , Jingbo B. Wang

We consider the complexity of the local Hamiltonian problem in the context of fermionic Hamiltonians with $\mathcal N=2 $ supersymmetry and show that the problem remains $\mathsf{QMA}$-complete. Our main motivation for studying this is the…

Quantum Physics · Physics 2024-05-01 Chris Cade , P. Marcos Crichigno

Constrained combinatorial optimization with strict linear constraints underpins applications in drug discovery, power grids, logistics, and finance, yet remains computationally demanding for classical algorithms, especially at large scales.…

Quantum Physics · Physics 2026-04-07 Yajie Hao , Qiming Ding , Xiao Yuan , Xiaoting Wang

We provide a method to prepare a warm-started quantum state from measurements with an iterative framework to enhance the quantum approximate optimisation algorithm (QAOA). The numerical simulations show the method can effectively address…

Quantum Physics · Physics 2025-02-17 Haomu Yuan , Songqinghao Yang , Crispin H. W. Barnes